Evaluation of Nutritional Status in Renal Transplant Recipients in Accordance with Changes in Graft Function

Decreased abdominal wall muscle mass defined by muscle ultrasound is associated with malnutrition according to Global Leadership Initiative on Malnutrition criteria in renal transplant recipients: A cross-sectional study

BACKGROUND

Changed body composition with increased fat content and decreased muscle mass is seen in renal transplantation recipients (RTRs). Increased fat mass might mask underlying muscle mass loss; measuring low body mass index and weight reduction alone may not be sensitive enough to diagnose malnutrition in RTRs. We aimed to determine the prevalence of malnutrition in stable RTRs using the Global Leadership Initiative on Malnutrition (GLIM) criteria and to assess the use of muscle ultrasonography (US) to compare the performance of various muscle US measurements in the diagnosis of reduced muscle mass.

METHODS

Ninety-one patients who had renal transplantation >6 months ago were enrolled in the study. GLIM criteria were performed for all patients, but not those at risk of malnutrition. Bioelectrical impedance analysis and muscle US were performed to identify reduced muscle mass.

RESULTS

The prevalence of malnutrition according to GLIM criteria was 25.3% (n = 23). All muscle US measurements were lower in the malnourished group than the well-nourished group; however, the malnourished group had substantially lower muscle thicknesses in abdominal muscles, specifically the external oblique (EO) and internal oblique (IO) muscles, than the well-nourished group (P = 0.001 and P = 0.007, respectively). There was a significant association between malnutrition and EO (odds ratio [OR] = 0.338, 95% CI = 0.163-0.699; P = 0.003) and IO (OR = 0.620, 95% CI = 0.427-0.900; P = 0.012) regardless of age and sex.

CONCLUSION

One in four RTRs experience malnutrition. Muscle US could be used effectively for the diagnosis of reduced muscle mass and malnutrition in RTRs according to GLIM criteria.

Application of Bioelectrical Impedance Analysis in Nutritional Management of Patients with Chronic Kidney Disease

Body composition measurement plays an important role in the nutritional diagnosis and treatment of diseases. In the past 30 years, the detection of body composition based on bioelectrical impedance analysis (BIA) has been widely used and explored in a variety of diseases. With the development of technology, bioelectrical impedance analysis has gradually developed from single-frequency BIA (SF-BIA) to multi-frequency BIA (multi-frequency BIA, MF-BIA) and over a range of frequencies (bioimpedance spectroscopy, BIS). As the clinical significance of nutrition management in chronic kidney disease has gradually become prominent, body composition measurement by BIA has been favored by nephrologists and nutritionists. In the past 20 years, there have been many studies on the application of BIA in patients with CKD. This review describes and summarizes the latest research results of BIA in nutritional management of patients with CKD including pre-dialysis, hemodialysis, peritoneal dialysis and kidney transplantation, in order to provide reference for the application and research of BIA in nutritional management of chronic kidney disease in the future.

The Effect of Higher and Lower Protein Intakes on Nitrogen Balance in Renal Transplant Recipients with Underlying Graft Dysfunction

It is essential to determine the optimum protein intake in renal transplant recipients on steroids with renal dysfunction to maintain a neutral nitrogen balance. Our aim was to study the effect of higher (1.2 g/kg/day) and lower (0.8 g/kg/day) protein intakes on nitrogen balance, body composition, glomerular filtration rate (GFR), and proteinuria in renal transplant recipients with low estimated GFR (eGFR) (15-44 mL/min/1.73 m²). This prospective, open-labeled, randomized, cross-over, interventional study enrolled patients who were ≥4 months posttransplant with eGFR between 15 and 44 mL/min/1.73 m². Subjects were randomized to either Group 1 [Diet: proteins (1.2 g/kg/day), 35 kcal/kg/day] or Group 2 [Diet: proteins (0.8 g/kg/day) and 35 kcal/kg/day] for one month. Subjects crossed over to the other diet for 2^nd month. Body composition analysis, serum creatinine, blood urea nitrogen, serum protein, serum albumin, 24-h proteinuria, GFR measurement (24 h creatinine clearance), three-day diet recall and nitrogen balance estimation were performed at baseline and at the end of the first and 2^nd month. Statistical analysis was performed using IBM SPSS Statistics version 21. Thirty-two of 35 patients completed the study. Three-day diet recall showed that daily protein and energy consumption was 1.2 g/kg and 36.47 kcal/kg with higher and 0.94 g/kg and 31.94 kcal/kg with lower protein diets, respectively. Nitrogen balance was +3.61 g/day (P = 0.0002) with higher and +1.66 g/day with lower protein diets. A significant increase was noted in muscle mass (P = 0.0317), blood urea nitrogen (P = 0.0118), GFR (P = 0.0114), and proteinuria (P = 0.010) with a higher protein diet. Renal transplant recipients remained in positive nitrogen balance with both diets. Muscle mass and proteinuria increased significantly with a higher protein diet.

Poor kidney graft survival in anorexia nervosa patients

BACKGROUND

Anorexia nervosa is a condition associated with poor outcomes in a variety of circumstances such as recurrence of eating disorders, psychiatric disorders, and organ damage.

OBJECTIVE

In the present study, we first sought to determine the 5-year kidney graft survival in patients with anorexia nervosa and then to evaluate the BMI course and medical complications.

METHODS

In this multicenter, retrospective, case-control study, we analyzed the impact of anorexia nervosa on graft outcomes compared to transplant recipients with low or normal BMI.

RESULTS

We enrolled 137 women in this study: 19 with anorexia nervosa, 59 with low BMI (BMI < 18.5 kg/m²), and 59 with normal BMI (18.5-24.9 kg/m²). Anorexia nervosa was significantly associated with lower graft survival compared to either of the other groups (hazard ratio 5.5 [95% CI 3.4-8.9], p = 0.005); there was no difference in graft survival between patients with low or normal BMI. Cardiovascular complications were more frequent in the anorexia nervosa group (37%) than in patients with low (6%) or normal BMI (7%) (p = 0.001).

CONCLUSION

We conclude that patients with anorexia nervosa should be considered a high-risk group.

LEVEL OF EVIDENCE

Level III, evidence obtained from well-designed cohort or case-control analytic studies.

Malnutrition according to GLIM criteria in stable renal transplant recipients: Reduced muscle mass as predominant phenotypic criterion

BACKGROUND & AIMS

Malnutrition has a negative impact on quality of life and survival in renal transplant recipients (RTR). Therefore, malnutrition detection is important in RTR, but this may be hampered by concomitant presence of weight gain and overweight. Recently, the Global Leadership Initiative on Malnutrition (GLIM) developed a set of diagnostic criteria for malnutrition. We aimed to assess the prevalence of malnutrition according to the GLIM criteria and the distribution of phenotypic criteria in RTR. Additionally, we examined the potential value of 24-h urinary creatinine excretion rate (CER) as alternative measure for the criterion reduced muscle mass.

METHODS

We used data from stable outpatient RTR included in the TransplantLines Cohort and Biobank Study (NCT02811835). Presence of weight loss and reduced intake or assimilation were derived from Patient-Generated Subjective Global Assessment (PG-SGA) item scores. Reduced muscle mass was assessed by multi-frequency bio-electrical impedance analysis (MF-BIA) and defined as an appendicular skeletal muscle mass index (ASMI) < 7 kg/m² for men and <5.5 kg/m² for women, and in additional analysis defined as creatinine-height index (CHI, based on 24 h urine CER) < 80%. Inflammation was present if C-reactive protein (CRP) was >5 mg/L. Malnutrition was defined as presence of at least one phenotypic (weight loss and/or low BMI and/or reduced muscle mass) and one etiologic criterion (reduced intake/assimilation and/or disease burden/inflammation).

RESULTS

We included 599 RTR (55 ± 13 years old, 62% male, BMI 27.2 ± 4.7 kg/m²) at a median of 3.1 years after transplantation. According to GLIM criteria, 14% was malnourished, of which 91% met the phenotypic criterion for reduced muscle mass. Similar results were found by using CHI as measure for muscle mass (13% malnutrition of which 79% with reduced muscle mass).

CONCLUSIONS

Malnutrition is present in one in 7 stable RTR, with reduced muscle mass as the predominant phenotypic criterion. Assessment of nutritional status, most importantly muscle status, is warranted in routine care, to prevent malnutrition in RTR from remaining undetected and untreated. The diagnostic value of 24-h urinary CER in this regard requires further investigation.

Healthy Eating Index of Living Donor Renal Transplantation Recipients During the First Year Posttransplant

BACKGROUND

The aim of this study was to examine the relationship between diet quality and weight gain in kidney transplant recipients from pretransplant baseline through posttransplant at 3 months and 1 year.

METHODS

Data from a prospective, observational cohort study of kidney transplant patients (n = 26) were analyzed. Participants were adult (aged 18-65 years), living donor kidney transplant recipients who were participating in a prospective body composition study. Body weight, body mass index, dietary intake, and Healthy Eating Index scores were used to assess changes in weight, nutrient intake, and diet quality.

FINDINGS

At the time of kidney transplantation, 42% (n = 11) were obese and 27% (n = 7) were overweight. Weight significantly increased from transplantation to 12 months (mean [SD]: 83 [18] kg and 90 [18] kg, respectively; mean change 8.4%, P = .002). At 12 months posttransplant, dietary fat intake significantly increased (P = .033). Body weight was strongly correlated with total dietary fat intake (r = 0.56, P = .003). The Healthy Eating Index total scores at baseline and 1-year posttransplant were not significantly different (45.75 [14.99] and 42.59 [12.70]). Likewise, component scores did not change from pretransplant to posttransplant.

DISCUSSION

Diet quality of transplant recipients was poor both before and after transplantation. Using the Healthy Eating Index confirmed that improvements in food intake are needed. Further research is warranted to identify dietary recommendations for the prevention of excessive weight gain and the potential adverse health complications following kidney transplantation.

High abdominal adiposity and low phase angle in overweight renal transplant recipients

Obesity is associated with increased risk of cardiovascular disease (CVD). Body mass index (BMI) is the most used parameter for obesity screening. However, the evaluation of CVD risk in overweight individuals should include the assessment of body fat distribution and body composition. Renal transplant recipients (RTR) have a high CVD risk and frequently present weight gain and loss of lean mass. The aim of this study was to evaluate body fat distribution and body composition in overweight RTR. This cross-sectional study was conducted with 86 RTR and 86 hypertensive individuals (comparison group, CG) presenting BMI 25-35 Kg/m² and 45-70 years. Anthropometric evaluation included BMI, waist circumference, waist-to-height ratio, and a body shape index. Body composition was evaluated with bioelectrical impedance analysis (BIA). Glomerular filtration rate was estimated (eGFR) by CKD-EPI equation. RTR group (RTRG) and CG presented similar age and BMI. RTRG when compared to CG presented lower percentage of women and eGFR; higher central adiposity; and lower values of reactance, intracellular water, body cell mass and phase angle, more consistently observed in women. This study suggests that overweight RTR present higher abdominal adiposity and impairment in BIA parameters that are sensitive indicators of impaired membrane integrity, water distribution, and body cell mass.

Comparative Analysis of Arterial Stiffness and Body Composition in Early and Late Periods After Kidney Transplantation

INTRODUCTION

Diseases of the cardiovascular system are the most common cause of death in patients after kidney transplantation (KTx). Pulse wave velocity (PWV) measurement is a simple, noninvasive, and increasingly popular method to assess arterial stiffness, and thus to assess cardiovascular risk. The aim of the study was to compare arterial stiffness and body composition in patients after KTx in the early and late postoperative periods.

METHODS

This research was carried out from January to November 2017 at two locations: (1) Department and Clinic of General and Transplant Surgery and (2) Nephrology and Transplantology Clinic Medical University of Warsaw, the Infant Jesus Teaching Hospital, Warsaw, Poland. The study group consisted of 30 patients in the early postoperative period (2-7 postoperative days) and 151 patients in the late period (6 months to 27 years) after KTx. A single blood pressure measurement, PWV, was performed using a Schiller BR-102 plus PWV. Body composition analysis was performed using a Tanita MC-780 device.

RESULTS

The average PWV for patients in the early period after KTx was 8.02 ± 2.21 m/s and in the late period 8.09 ± 1.68 m/s. Positive correlations were found between adipose tissue in the abdominal cavity (R = 0.444, P = .033) and PWV value. There was no correlation between the values of PWV and time after transplantation (R = 0.034, P = .777). Upon analyzing patients after transplantation and taking into account the type of dialysis therapy, lower systolic blood pressure (142 ± 21 mm Hg vs 156 ± 24 mm Hg) and diastolic blood pressure (84 ± 13 mm Hg vs 98 ± 11 mm Hg) values were observed in patients treated with hemodialysis compared with those treated with peritoneal dialysis.

CONCLUSION

Using PWV measurement, we found that arterial stiffness levels were similar for early and late periods after transplantation.

Nutritional status, energy expenditure, and protein oxidative stress after kidney transplantation

OBJECTIVES

To evaluate the association between nutritional status, resting energy expenditure (REE), and protein oxidative stress in patients after kidney transplantation (KT).

METHODOLOGY

The study evaluated 35 patients transplanted at the time of hospital discharge and 3 months after regarding: body composition, REE (by indirect calorimetry), and injury factor (IF); serum urea, creatinine, glucose, albumin, total protein, advanced oxidation protein products (AOPP), vitamin C.

RESULTS

Three months after discharge, there was an improvement in renal function, nutritional status, and oxidative stress, with a standardization in the REE/kg. There was an increase in body weight, mainly in fat mass. The correlations showed that a greater cold ischemia time resulted in a deeper decline in vitamin C; a longer hospital length stay resulted in a greater reduction in AOPP; the higher preoperative body weight showed greater increases in body fat and glucose after transplantation. For decreases in REE and IF, there were increases in total protein. Finally, at hospital discharge there was a greater gain in weight, lower albumin, and total protein among individuals who had rejection episodes.

DISCUSSION

The KT improves many of metabolic abnormalities, with the improvement of nutritional status, oxidative stress, and normalization of REE.

Assessment of Arterial Stiffness, Volume, and Nutritional Status in Stable Renal Transplant Recipients

Reduction of cardiovascular death might have a significant effect on the long-term survival rates of renal transplant recipients (RTRs). The aim of the study was to assess the relation between arterial stiffness and graft function, adipose tissue content, and hydration status in patients after kidney transplantation (KTx).The study included 83 RTR patients (mean age: 55 ± 13 years) who had been admitted to a nephrology-transplantation outpatient clinic 0.5 to 24 years after KTx. Clinical and laboratory data were analyzed and eGFR was calculated with the CKD-EPI formula. Arterial stiffness was assessed in all RTRs with pulse wave propagation velocity (PWV) with the use of a complior device. In addition, fluid and nutritional status was assessed with a Tanita BC 418 body composition analyzer. The control group consisted of 31 hospital workers who received no medication and had no history of cardiovascular disease.Multivariable linear regression analysis, with PWV as a dependent variable, retained the following independent predictors in the final regression model: red blood cell distribution width (RDW) (B = 0.323; P = 0.004), age (B = 0.297; P = 0.005), tacrolimus therapy (B = -0.286; P = 0.004), and central DBP (B = 0.185; P = 0.041). Multivariable linear regression analysis with eGFR as a dependent variable retained the following independent predictors in the final regression model; creatinine concentration (B = -0.632; P = 0.000), hemoglobin (B = 0.280; P = 0.000), CRP (B = -0.172; P = 0.011), tacrolimus therapy (B = 0.142; P = 0.039), and triglycerides (B = -0.142; P = 0.035).Our data indicates that: kidney transplant recipients can present modifiable CVD risk factors linked to increased arterial stiffness, DBP, waist circumference, SCr, time on dialysis, CyA therapy, and visceral fat mass; RDW is a parameter associated with arterial stiffness; and parameters such as CyA therapy, time on dialysis, PWV, RDW, and triglycerides show negative associations with the allograft function assessed with eGFR.